<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Contain 容器</title>

    <link rel="stylesheet" href="css/bootstrap.min.css">
    <script src="js/jquery-3.4.1.min.js"></script>
    <script src="js/bootstrap.bundle.min.js"></script>
    <script src="js/bootstrap.min.js"></script>

    <style>
        div{
            border: 1px solid red;
        }
    </style>
    
</head>
<body>
    <!-- 
        class="container":可以根据浏览器的大小进行自适应和居中
        
        ps：会设置padding属性为15
     -->
    <div class="container">
        <h2>hello 酷狗</h2>
    </div>

    <div class="container-fluid">
        <h2>哈哈哈哈</h2>
    </div>
</body>
</html>